Can you change the shader and font settings as a new default?
For the first question about the keyboard shortcuts


Go to Blender User preferences window [Ctrl+Alt+U] under the "Input Tab"
Search for "Context toggle values" in the search field.
Scroll down to the "3D View" category
You should see three entries by default for [Z] [Alt+Z] and [Shift+Z]
key combinations.
Expand each of them and change the strings in the "Value" fields to whatever you want.
In you case change the [Shift+Z] to toggle between "MATERIAL" and "RENDERED"